1. Field of the Invention
Exemplary aspects of the present invention relate to an image forming apparatus and an image forming method, and more particularly, to an image forming apparatus and an image forming method capable of automatically collecting a developer from a development device.
2. Description of the Related Art
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction printers having at least one of copying, printing, scanning, and facsimile functions, typically form an image on a recording medium (e.g., a recording sheet) based on image data using electrophotography. Thus, for example, a charger uniformly charges a surface of an image carrier; an optical writer emits a light beam onto the charged surface of the image carrier to form an electrostatic latent image on the image carrier according to the image data; a development device supplies toner particles to the electrostatic latent image formed on the image carrier to make the electrostatic latent image visible as a toner image; the toner image is directly transferred from the image carrier onto a recording sheet or is indirectly transferred from the image carrier onto a recording sheet via an intermediate transfer member; a cleaner then cleans the surface of the image carrier after the toner image is transferred from the image carrier onto the recording sheet; and finally, a fixing device applies heat and pressure to the recording sheet bearing the toner image to fix the toner image on the recording sheet, thus forming the image on the recording sheet.
In such image forming apparatus, a two-component developer containing both toner particles and carrier particles is automatically collected from the development device to replace the developer with a fresh developer. For example, the development device installed in the image forming apparatus automatically removes the developer degraded over time from the development device. Thereafter, the empty development device is filled with the fresh developer.
In one example of the image forming apparatus, a regulating member contacts a development sleeve, serving as a developer carrier, to scrape off any developer carried by the development sleeve, so that the scraped developer falls into a collection container.
In another example of the image forming apparatus, an outlet, which is opened and closed by a shutter, is provided in a developer circulation path of the development device. When the shutter is opened, a developer is discharged from the development device through the outlet.
In yet another example of the image forming apparatus, an outlet is provided near the developer circulation path of the development device. When a screw is reciprocally rotated forward and backward, a developer is discharged from the development device through the outlet.
In the above-described image forming apparatuses, when the developer is collected automatically from the development device, a surface of an image carrier, such as a photoconductive drum or a photoconductive belt for carrying a toner image, may be damaged, or a cleaning blade contacting the image carrier may be curled.
Specifically, when the development device is driven to automatically collect the developer from the development device while the image carrier is not driven, the developer carried by the developer carrier may slide over the image carrier intensively when the developer is not yet collected sufficiently, generating a band-shaped scratch on a part of the image carrier. The band-shaped scratch may then show up as a band-shaped image on a recording sheet.
On the other hand, when the image carrier is driven together with the development device to automatically collect the developer from the development device, another malfunction may occur. Specifically, the developer carrier hardly carries the developer after the developer is collected from the development device sufficiently, and therefore does not supply enough toner particles to the image carrier. Accordingly, toner particles may not be sufficiently supplied to an edge of the cleaning blade contacting the image carrier to remove residual toner particles adhered to the image carrier. Consequently, the cleaning blade may be curled. The curled cleaning blade may damage the image carrier or may generate secondary malfunctions, such as faulty cleaning and noise.